Avalanche Forecast

Issued: Feb 7th, 2021 4:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Storm Slabs and Wind Slabs.

Avalanche Canada ahanna, Avalanche Canada

In the south of the region the main concern is fresh storm slabs as well as loose dry sluffing in the new snow.

In the north, the main concern is wind slabs at upper elevations only, so avalanche danger below treeline can be treated as LOW.

See the problems tab for more details. 

Summary

Confidence

Moderate - Recent weather patterns have resulted in a high degree of snowpack variability within the region.

Weather Forecast

Sunday night: Mostly cloudy with flurries, up to 10 cm in the south, light northwest ridgetop wind, alpine temperature -15.

Monday: Mix of sun and cloud, light to moderate northwest ridgetop wind, alpine high -15.

Tuesday: Mix of sun and cloud, light northerly ridgetop wind, alpine high -22.

Wednesday: Sunny, light to moderate northerly ridgetop wind, alpine high -22.

Avalanche Summary

Size 1 skier triggered wind/storm slabs have been reported every day since Thursday throughout the region. Check out this MIN report describing a skier accidental storm slab avalanche in the Coquihalla area Saturday.

Last week there were reports of natural, explosive and human triggered avalanches size 1-2, including a widespread natural avalanche cycle Monday night. Many of these failed on the recently buried persistent weak layer.

Snowpack Summary

Snowfall in the south of the region is forecast to conclude Monday morning, after dropping 40-70 cm of snow over the last 72 hours. In the north, localized areas of soft wind slab may sit over a crust on solar aspects. Recent variable wind directions have resulted in wind loading in atypical terrain features.

30-80 cm of recent snow sits on a persistent weak layer that consists of facets at upper elevations, surface hoar in sheltered areas, a melt-freeze crust below 1600 m, and a sun crust on south-facing slopes. 

In the south, the underlying snowpack is well consolidated. In the north, a melt-freeze crust from early December may be found 100 to 200 cm deep. Recent reports suggest that this layer is gaining strength and it has been unreactive in recent weeks.

Terrain and Travel

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
  • Be careful as you transition into wind affected terrain.

Problems

Storm Slabs

An icon showing Storm Slabs

A storm slab problem exists in the south of the region, where recent snowfall has been significant (40-70 cm). Cooling temperatures will help to lock up storm slabs but some residual reactivity may still be observed in wind loaded features. Loose dry sluffing may also be observed in the new snow from overnight.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Wind Slabs

An icon showing Wind Slabs

A wind slab problem exists in the north of the region. Wind slabs may remain reactive especially where they sit over a crust on solar aspects, at ridgetops and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Feb 8th, 2021 4:00PM